Radioreceiving apparatus



y 1932- H. J. J. M. DE R. DE BELLESCIZE 7, 9

RADIO RECEIVING APPARATUS Original Filed March so. 1927' INVENTOR mu. m. de a. pmscnzs ATT RNEY Patented July 12, 1932 UNITED STATES PAraNr OFFICE HENRI JEAN .rosarn mm 151: BEGNAULD m: ammonia, or rams, ramcn, AB-

SIGNOR TO RADIO CORPORATION 01 AME OF DELAWARE RICA, OI NEW YORK, N. Y., A CORPORATION mmonncnrvnio Arrm'rus Application filed larch 80, 1927, Serial No.'179,469, and in France April 13,1926. Renewed September associated therewith for compensating the effects due to fading.

In certain equipments fed with alternating current. or alternating currentpotentials of sinusoidal wave form, either modulated or periodically interrupted, it happens on account of certain accidental causes that the current or the alternating current potential s subject to more or less great variationsun amplitude. Now, it is often necessary, with a view to preserve the apparatus, for the sake or regulation or simply of the quality of reproduction, that the indicator apparatus should carry a current which, 'while faithfully reproducing the modulations or interruptions of the feed currents or potentials, is entirely freed or safeguarded from accidental variations of its mean amplitude.

Among such cases in Which this problem arises, there figures chiefly that of transmission with Hertzian waves subject to what is known as fading.

The present invention discloses a solution to the problem which is useful for distribution by alternating current both permanent as well as modulated or periodically interrupted, provided that the frequency of modulation or interruptions should be higher than that of accidental alterations, when this condition is mostly fulfilled. In the case of direct current distribution, it would be suiiicient to change first into alternating current by the aid of a converter of well-known kind.

It has already been suggested to interpose between the supply and the indicator a coupling means whose sensitiveness diminishes automatically as soon as the current in the indicator exceeds a certain pre-arranged value, and this reduction was ordinarily insured by the aid of a variable resistance. The inconvenience residing in devices of this kind consists in that to each value of the current in the indicator there corresponds one and only one value of the variable resistance, and therefore of the sensitiveness of the coupling means.

However, it is necessary, and this is accomplished by the present invention, that every increase or decrease, no matter 'how the slight departure that has given rise thereto. It is moreover desirable, once that the mean current in the indicator has been restored to the desired value, that the sensitivity of the transmission should be fixed to a predetermined value instantaneousl as sumed in order to insure such result, an this, unt1l a fresh change in the supply current or potential occurs.

In other wordsjthe supply current and current in the indicator should be connected 1 by a transmission device acting similarly as a servo-motor.

The invention, both as to its construction and mode of operation together with the objects and advantages thereof, will best be understood by reference to the following description taken in connection with the accompanying drawing in which Fig. 1 is a circuit arrangement embodying the features of my invention,

2 is a modification thereof, and

Fig. 3 is an arrangement applying the schemes shown in Figs. 1 and 2 toHertzian wave receivers for the purpose of compensating the effects due to fading. I

The scheme shown-in Fig. l-is especially adapted to regulation of sinusoidal currents or signals on carrier waves. The current coming in at 1 actuates an indicator 14 through the intermediary of transformer 2, relay 4 and transformer 12, the latter coupling the output of relay 4 and indicator 14. The relay 4 may be, for instance, an arc relay, or a vacuum tube, comprising one or more control electrodes. The sensitiveness of the relay depends upon the permanent potential applied to one of its electrodes 3, the said potential being derived from the plate a of condenser C, the charge of which therefore governs the sensitivity. In order that this charge may assume or preserve a convenient value at all instants, the condenser C is fed across a resistance R from one of the two sources 5 or 6 cut in the circuit by means of a mobile con- 'tact or armature 10 adjusted by a spring 9 and bearing upon one of the contacts 7 or 8. The connection in circuit of the source 5 for a sufliciently longl time imparts a maximum of sensitivity to t e relay, while when source 6 is connected in circuit, the sensitivity is considerably diminished. (In the majority of rela s, the maximum sensitivity is obtained by rep acing the source.5 by a conductor connecting the contact 7 wlth the relay). The movable contact or armature 10 in turn is controlled by the output current of the relay through transformer 13. If the mean value of this current is unduly low, the armature will come to bear upon contact 7, and this results in a gradual increase in sensitivity to such an amount as may be required. If the current in the indicator is too high, the armature comes to incidental result that the sensitivity is diminished. Finally, if the current preserves its pre-arranged value, the armature having but a small stroke or travelling distance, remains between contacts 7 and 8 so that the sensitivity remains unaltered, save for the losses occasioned in condenser C. By way of example, there is shown for the drove 11-9 of armature 10 a device of known kind adapted to thermal ammeters which by contacts 7-8 allows of regulation of the main valve of the current recelved bythe indicator. Similarly as in a servo-motor, it is possible in this scheme to adjust the rate of variation of sensitivity by adjusting the time constant RC. ThlS time constant must be consider-' ably higher than the time .of shift of contact 10, while it' must be lower thanthe period of accidental alterations to be compensated.

Fig. 2 shows a modification adapted to the regulation of periodically interrupted currents such as the currents used in telegraphy work. For this purpose, the source 5 is omitted and the condenser C is shunted by a re sistance R a preciably higher than the resistance R. s long as the current coming from the relay 4 is too low, the movable contact or armature 10 will never reach the contact 8 and the condenser C will get a chance to discharge completely into the resistance R whereby the sensitiveness of the relay is gradually increased to a maximum. On the contrary, in the course of transmission by undul intensive signals, the armature 10 is incessantly in movement passing from contact 7 during spaces betweensignals to contact 8 while signals are proceeding. Hence, alternating dischar es and charges take place in the condenser a thelatter changing it suddenly on account of the relation R and B. This differential action makes'the relay gradually insensitive until the armature 10 no longer reaches the contact 8.

3 illustrates an application of this regulator-to a receiver acted upon by Hertbear upon contact 8 with the zian waves and here shown elementary illustration.

The signals on modulated or chopped waves are received by the antenna 1' and the tuned circuit 2',thence fed to the regulator tube 4, and thereafter detected by tube 18. If at this point, their intensity is not. yet sufiicient to actuate the armature 10, they may be amplified by one stage for direct current, comprising in well-known manner a relay 24, a plate resistance 23 and a source 22, capacities 19 20 and the coil 21 stopping the flow of radio frequency oscillations to the relay 11 the proximity of which to tube 4 is liable to occasion oscillations. The relay 11 may be of any desired type, for instance, of the moving coil type, and it is passed by a current I,,+I,, (plate current and signal current, respectively). By tensioning more or less the spring 9 or shifting the row of contacts 78, it is possible to cause contact 7 to become operative for any desired value of the current less than the pro-arranged value I,,+I,, and contact 8 for all higher values. 'A reverser 16 (commutator switch) allows of changing operating conditions from reception on carrier waves to operation and reception on broken waves. A milliamme'ter 26 is provided to insure proper operation. The indicator is shown at 14' coupled capacitively to the output of relay 24.

By virtue of the automatic feature of the regulation here 'disclosed, it is possible for the receiver apparatus to handle signals of widely varying volumes without the necessity of manipulation of any kind, regardless of whether the corresponding station is located a few kilometers or a few thousand kilometers away.

only in its most This regulating device is indispensable to insure proper function of certain parts of receiving equipment, for instance, in the operation of the differential arrangement comprising frictional means disclosed in the French Patent No. 587,625 filed December 28,

1923 indeed, in the absence of such protective means, the excess of energy coming in on the signal at any given time is apt to derange the differential device. And when allowed to go too far, such excess of energy may even cause disappearance of the signals, according to the mechanism provided for disturbance and interference.

It must be noted that the present invention comprises all modifications, servo-motors, static elements, and other, adaptedto auto matically Vary the sensitivity in the desired sense, in a continuous or intermittent manner, until the pre-arranged value for the indicator is restored.

Having thus described my invention, I claim:

1. Radio receiving apparatus of the class described, comprising a high frequency amparts for the sake of-clarity of plifier, an electromechanical relay controlled y the output of said amplifier, said relay having an armature connected to the control electrode of the amplifier, and a air of contacts raised to different potentia s arranged to cooperate with said armature, whereby variations in mean signal intensity will actuate the relay armature to contact with one or the other of said contacts to maintain the signal intensity substantially-constant.

2. Radio receiving apparatus of the class described, comprising a thermionic amplifier, indicatng means coupled to the output thereof, and means for compensating for any variation in mean signal intensity in said indicating means comprising an electromechanical relay coupled to the amplifier output, a condenser connected between cathode and control electrodes of the amplifier, said relay having an armature connected to one terminal of the condenser, and a pair of contacts and polarizing means connected to the other terminal of the condenser, the relay armature normally assuming a position intermediate said contacts and contacting with one or the other thereof when the signal intensity in the amplifier output is above or below the mean signal intensity.

3. Radio receivingapparat-usoftheclassdescribed, comprising a high frequency ampli fier, indicating means coupled to the output thereof, and means for compensating for any variation in mean signal intensity in said indicating means comprsing an electromechanical relay coupled to the amplifier output, a condenser connected between cathode and control electrodes of the amplifier, said relay having an armature connected to one terminal of the condenser through a resistance, and a pair of contacts and grid polarizing means connected to the other terminal of the condenser, the relay armature normally assuming a position intermediate said contacts and contacting with one or the other thereof when the signal intensity in the amplifier output is above or below the mean signal intensity.

4. In radio receiving apparatus of the class described, the combination with a high frequency amplifier, of an indicator coupled to the output of said amplifier, and means for compensating for any variation of the mean signal intensity in the indicator, said means comprising a condenser connected between cathode and control electrodes and an electromechanical relay controlled by the amplifier output for charging said condenser in'p oportion to resulting variations, said condenser charge arranged to influence the control electrode for maintaining the mean signal intensity substantially constant.

5. Apparatus for maintaining the output of an electron discharge device substantially constant despite fading fluctuations in the in put thereof comprising, an electron discharge device having an anode, a cathode and a coning, an electron discharge device having an anode, a cathode, and a control electrode; input and output circuits coupled thereto; means for controlling the amplification of the device inversely to the average amplitude of the output thereof; and means for controlling the speed of action of the said last mentioned amplification control means.

7 Apparatus for maintaining the output of an electron discharge device substantially constant despite fading fluctuations in the input thereof comprising an electron discharge device having an anode, a cathode, and a control electrode; input and output circuits coupled thereto; means for utilizing a portion of the energy in the output circuit for maintaining the output energy constant despite fluctuations in the energy in the input circuit; and means for controlling the time at which energy taken from the output circuit for maintaining the output energy relatively constant, acts.

8. The method of automatically varying the sensitivity of a high frequency amplifier inversely to variations ofv intensity of received signals applied to the input circuit of the amplifier which includes capacitively storing electrical energy, impressing potentials derived from the capacitively stored energy of appropriate values on the control electrode of the amplifier to compensate for any change in the mean value of the currents in the output of said amplifier; the value of the impressed potentials being-determined by the amplifier output.

9. Apparatus for, maintaining the output of a high frequency amplifier including an electron discharge tube substantially constant despite fading 'fluctuations in the input thereof, said tube havin an anode, a cathode and a control electrode, nput and output circuits coupled thereto, a path including a visual current indicator and means responsive to the amplifier output for applying a control potential to the control electrode of said tube, and means for controlling the time at which the applied control potential makes itself manifest upon the control electrode.

10. Apparatus for maintaining the output of an electron discharge device substantially constant despite fading fluctuations in energy supplied to the input thereof'comprisin an electron discharge device having an anode, a

cathode, and a control electrode input and v mg a visual current indicator and means vice inversely to the average amplitude of the output thereof, and means for controllin the speed of action of the said last mentione amplification control means. a

11. In a high frequency receiving system, an electron discharge device having an anode circuit, a cathode and a grid, a tuned circuit connected between said cathode and grid whereby said receiving system ma be adjusted to respond to current ofa esired frequency, sound reproducing means, means for supplying current from said device to said sound reproducing means, means for controlling the'static potential on said grid in response to the intensity of the received carrier thereby to produce a substantially constant volume of sound from said sound reproducing means over a range of intensities of received current, means responsive to the magnitude of current flowing in said anode circuit for visually indicating said magnitude,

and additional means for controlling the time at which the static potential makes itself manifest on said grid.

12. In combination, in a radio receiver, a high frequency amplifier having a resonant input circuit, a detector having its input electrodes coupled to the output circuit of said amplifier, a reproducer, means for connecting the reproducer to the output of said detector, a path connecting said detector output to said resonant circuit of said amplifier, said path includinga resistor for controlling the static potential on the grid of the amplifier in response to the intensity of received current thereby to produce a substantially constant volume of sound from said reproducer over a range of intensities of received current, a condenser connected to said resistor in the input circuit of said amplifier said condenser having a magnitude such that the time at which the said static potential makes itself manifest on said grid is controlled, and a visual current indicator connected to said aforementioned path.

HENRI JEAI JOSEPH MARIE dc REGNAULD de BELLESCIZE.

output circuits coupled thereto, a path in- 'clu for controlling'the amplification of the de- DISCLAIMER 1,867 ,139.Henri Jean Joseph Marie de Regnauld de Bellescize, -Paris, France. RADIO RECEIVING ArrARA'rUs Patent dated July 12, 1932. Disclaimer'filed September 30, 1933, by the assignee, Rodin Corporation of America. Hereby enters this disclaimer to the said claims of said Letters Patent which are in the following words, to-wit:

- 5. Apparatus for maintaining the output of an electron discharge device substantially constant despite fading fluctuations in the input thereof comprising, an electron discharge device having an anode; a cathode and a control electrode; input and output circuits coupled thereto; means responsive to the output for applying a control potential to the control electrode of the electron dischar e device; and means for controlling the time at which the applied control potentia makes itself manifest upon the control electrode.

6. Apparatus for mamtammg the output of an electron dischargedevice substantially constant despite fading fluctuations in energy supplled to the input' thereof comprising, an electron discharge device having. an anode, a cathode, and a control electrode; input and output circuits coupled thereto; means for controlling the amplification'of the device inverselyto the average amplitude of the output thereof;

and means for controlling the speed of action of the said last mentioned amplification control means. 7

7. Apparatus for maintaining the output of an electron discharge device substantially constant despite fading fluctuations in the input thereof comprising an electron discharge device having an anode, a cathode, and a control electrode; input and output circuits coupled thereto; means for utilizing a portion of the energy in the output circuit for maintaining the output energy constant despite fluctuations in the energy in the input circuit; and means for controlling the time at which energy taken from the output circuit for maintaining the output energy relatively constant, acts.

8. The method of automatically varying the sensitivit; of a high frequency amplifier inversely to variations of intensity .ofreceived signa s applied to the input circuit of the amplifier which includes capacitively storing electrical energy, impressing potentialsde'rived from the capacitively stored energy of appropriate values on the control electrode of the amplifier to compensate for any change in the mean value of the currents in the output of said amplifier; the value of the impressed potentials being determined by the amplifier output.

[Ofio'ial Gazette October 31 93 8.]. 

